Destroy X target artifacts and/or creatures. For each permanent destroyed this way, its controller reveals cards from the top of their library until an artifact or creature card is revealed and exiles that card. Those players put the exiled cards onto the battlefield, then shuffle their libraries.

If a player controls no permanents destroyed this way, that player reveals no cards from their library and doesn’t shuffle it.

2/9/2017

If an artifact or creature is targeted but not destroyed (perhaps because it gained indestructible or became an illegal target), it doesn’t count as one of the artifacts or creatures destroyed this way. An artifact or creature that’s destroyed but put into a zone other than a graveyard (such as a player’s commander in the Commander variant) does count.

2/9/2017

While revealing cards, a player stops as soon as they reveal a card that’s an artifact or a creature (or both). That player doesn’t choose one type.

2/9/2017

If a player’s library no longer contains an artifact or creature card when instructed to reveal cards, that player reveals the entire library, exiles no cards, and then shuffles it.

2/9/2017

All of the exiled cards are put onto the battlefield at the same time.